Hydrogen Fuel Cells

What is a hydrogen fuel cell?

With only pure water and useful heat as byproducts, fuel cells directly convert the chemical energy in hydrogen to electricity. Hydrogen fuel cell technology is the most energy efficient technique for extracting power from e-fuels. The hydrogen fuel cells also provide clean power for various applications no matter how large the installation is, as well as being pollution-free and having more than two times the efficiency of traditional combustion technology. As there are no moving parts, fuel cells operate silently and with high reliability.

Fuel Cell History

The first fuel cell was created by Sir William Robert Grove, a Welsh scientist and barrister in 1839. Through mixing hydrogen and oxygen in the presence of an electrolyte, he produced electricity and water.

In 1938 Christian F. Shoenbein, a German Swiss scientist, built on the work that Grove had done and managed to create the first observed fuel cell effect.

Over 20 years later, the first practical fuel cell applications happened in the U.S. space program. In the early 1960s, General Electric developed the first polymer membrane fuel cells which were then used in the Gemini Program. The Apollo Program then followed by using the fuel cells to generate electricity for life support, guidance and communications.

Decarbonization using hydrogen fuel cells

Through the usage of hydrogen together with fuel cell technology, it is possible to radically reduce the emissions from carbon dioxide, nitrogen oxides and particles from several sectors.

Hydrogen fuel cells provide great environmental benefits particularly when green hydrogen can be procured. Today, the amount of green hydrogen is not abundant but a lot of industry players are working towards green hydrogen production. It is also notable that a fuel cell is about twice as energy efficient as an internal combustion engine if used in a regular car or boat, for example.

Green hydrogen and fuel cells enable the energy transition

When produced from clean electricity, hydrogen together with fuel cells is seen by many as a critical enabler of the global transition into sustainable energy, as well as a vital component of achieving net-zero emissions economies.

Nonetheless, the global hydrogen market is on the uprise for all the right reasons, and hydrogen will continue to play an important role as an energy carrier, which enables the energy transfer from one place to another.

PEM Fuel Cells

Proton Exchange Membrane (PEM) fuel cells are the most researched as well as the dominating fuel cell technology. The PEM fuel cells are primarily developed for portable, transportation and stationary power generation purposes.

This type of fuel cell also:

  • Operates at ambient temperatures that range from -40 to 120°C
  • Have high peak power density
  • Use hydrogen gas with high purity as fuel

The electrolyte that is used is a solid proton exchange polymer membrane with good thermal and mechanical stability. However, it requires expensive electrocatalysts, mostly platinum, to support the reactions that occur at low temperatures.

Direct methanol fuel cell (DMFC)

Methanol is the fuel used for a DMFC, which is fed directly into the fuel cell’s anode system, often mixed with water. Because of the system’s lower output power of less than 100 watts, this fuel cell technology is often used to power cell phones or other smaller portable electronic applications.

Solid oxide fuel cell (SOFC)

The SOFC operates at an extremely high temperature of 1000 °C. This enables the reformation of fuels in the internal chemical process of the fuel cell. Compared to PEM fuel cells, which can only use 100% hydrogen as fuel, the SOFC can also use natural gas or biogas as feedstock. The start-up time for a solid oxide fuel cell is typically more than 2.5 hours.

Alkaline fuel cell

Alkaline fuel cell technology is closely related to PEM fuel cell technology, which uses an alkaline membrane instead of an acidic membrane. The main challenge of the fuel cell is its sensitivity to CO2, which can affect fuel cell performance. The typical power density of the alkaline fuel cell is 150 mW cm -2 with a power range of 70 W to 6 kW. Current applications include portable military and residential micro-CHP.

Fuel cells for different usage

  • Marine fuel cells: The current generation of fuel cell systems and the deployment of hydrogen supply infrastructure benefits hydrogen electrification solutions installed on vessels that operate inland and on coastal routes, including ferries, ROPAX and canal ferries with a power range from 500 kW up to several megawatts.
  • Aviation fuel cells: Among the various types of fuel cells devices, Proton Exchange Membrane Fuel Cell and Solid Oxide Fuel Cell operates at high temperature and uses a dense ceramic layer as an electrolyte while Proton Exchange Membrane Fuel Cell operates at low temperature and employs proton conducting membrane as the electrolyte.
  • Stationary fuel cells: Stationary power can be divided into three areas: primary, peak and back-up power. Primary power is where the fuel cell runs your site independently or connected to the grid, peak power helps you compensate for lack of power at times of high demand, and back-up power is where the fuel cell system steps in to keep your operation going when there is a power failure.
  • Off-road fuel cells: The drive cycle of a heavy-duty machine has two main characteristics: high operating time and high energy demand during shorter periods of lifting or towing. A PEM fuel cell can provide energy with a short start-up time, and the time required to refuel hydrogen is comparable to that of a diesel vehicle.

What are the major components of a fuel cell?

  • Anode: The hydrogen passes through the anode of a fuel cell and a catalyst splits the hydrogen molecules into electrons and protons.
  • Cathode: The oxygen passes through the cathode, and the protons, electrons and oxygen combine to produce water molecules.
  • Electrolyte membrane: the protons pass through the porous electrolyte membrane, while the electrons are forced through a circuit, generating an electric current and excess heat.

FAQ

  • From a technological point of view, a fuel cell is an electrochemical cell that converts the chemical energy of a fuel, which is often hydrogen, and an oxidizing agent, often being oxygen, into electricity through a pair of redox reactions.

    The fuel cell generates electricity through an electrochemical reaction in which said hydrogen and oxygen are combined to generate:

    • Electricity
    • Heat
    • Water

  • Hydrogen fuel cells can be used in a broad range of applications, some of which are:

    • Powering buildings
    • Powering cars
    • Hospitals
    • Emergency response systems
    • Powering trucks
    • Portable electronic devices
    • Backup power systems
    • Data centers
    • Telecommunications towers
    • Military applications for national defense